Dozna obremenitev in kvaliteta slik pri računalniškotomografskih kardioloških preiskavah z visoko pitch vrednostjo : diplomsko delo

Jazbec, Katarina (author), Vodeb, Pia (author), Starc, Tina (mentor), Mišič, Jure (comentor)

Uvod: Računalniškotomografske (CT) preiskave srca in njegovega žilja z visoko pitch vrednostjo predstavljajo velik napredek pri kardioloških preiskavah zaradi dveh prednosti, krajšega časa izvedbe ter možnosti zmanjšane dozne obremenitve za preiskovanca. Z uporabo veliko višje pitch vrednosti in prospektivnega načina slikanja omogočimo zajem podatkov celotnega srca v samo eni fazi njegovega cikla. Namen: Namen naloge je ovrednotiti, katere so prednosti in slabosti tehnike z visoko pitch vrednostjo pri CT slikanju v kardiologiji na področju dozne obremenitve in kakovosti slike, ter poiskati morebitne razlike med drugo in tretjo generacijo CT sistema z dvema izvoroma. Ugotoviti želimo, kateri dejavniki pri tehniki z visoko pitch vrednostjo vplivajo na dozno obremenitev in kakovost slike, ter kakšne so posledice spreminjanja le teh. Metode dela: V diplomskem delu sva uporabili deskriptivno metodo s sistematičnim pregledom literature, ki je bila iskana v slovenskem in angleškem jeziku. Primerjali sva rezultate raziskav, izvedenih v zadnjih 10 letih, na področju tehnike z visoko pitch vrednostjo. Rezultati: Raziskave sva med seboj primerjali glede na dozno obremenitev in kakovost slike, pri čemer so rezultati razdeljeni glede na uporabljeno generacijo CT sistema z dvema izvoroma. Pri prvem podpoglavju sva se osredotočali na produkt doze in dolžine polja, CT dozni indeks ter efektivno dozo. V drugem sva omenjali razlike med kvantitativnimi in kvalitativnimi ocenami, kjer sva se poglobili tudi v pogostost pojava artefaktov. Najnižja izračunana povprečna efektivna doza je znašala 0,2 ± 0,0 mSv. Pri večini raziskav so kvalitativne rezultate tehnike z visoko pitch vrednostjo ocenili kot odlične, zelo malo pa je bilo prisotnih koronarnih segmentov z nezadovoljivo diagnostično kvaliteto. Razlike v kvantitativni oceni slik so bile med posameznimi avtorji zelo majhne. Uporaba tehnike z visoko pitch vrednostjo je avtorjem omogočala izvedbo preiskav z zelo nizkim odstotkom pojava artefaktov gibanja. Razprava in zaključek: Glede na dobljene rezultate najine raziskave lahko sklepamo, da ima tehnika z visoko pitch vrednostjo pomembno vlogo pri zniževanju dozne obremenitve pacienta in hkrati ohranjanju zadovoljive kakovosti slike. Raziskava je lahko podlaga za nadaljnje preučevanje prednosti omenjene tehnike z izvedbo meritev na fantomu, pri čemer bi lahko dobili objektivne rezultate kakovosti slik in hkrati merili dozno obremenitev.

• Language: Slovenian
• Keywords: računalniška tomografija, pitch vrednost, dozna obremenitev, kakovost slike
• Work type: Bachelor thesis/paper
• Organization: ZF - Faculty of Health Sciences
• Year: 2019
• PID: 20.500.12556/RUL-110286
• COBISS.SI-ID: 5684331
• Publication date in RUL: 13.09.2019

Secondary language

• Language: English
• Title: Radiation exposure and image quality of cardiological examinations with high-pitch computed tomography : diploma work

Abstract

Introduction: Computed tomography (CT) examinations of heart and its vascular system with high pitch value represent great progress in cardiologic examinations because of two advantages, short scan time and the possibility of lower radiation exposure for the patient. With the use of high pitch values and prospective scanning technique we can scan the entire heart in just one phase of its cycle. Purpose: The purpose of our study was to evaluate the andvantages and disadvantages of high pitch scanning technique in cardiologic CT in the field of radiation exposure and image quality and find the differences between second and third generation of dual source CT systems. Our focus was on the factors of high pitch technique which may have the impact on radiation exposure and image quality and see if their change has any consequences. Methods: In our diploma work we used descriptive method of work with systematic literature review. The literature was searched in Slovenian and English language. We compared the results of the studies made in the last 10 years in the field of CT protocols with high pitch values. Results: The results of different studies were compared in the field of radiation exposure and image quality and separated based on the used generation of dual source CT system. In the first part our focus was on dose-lenght product, CT dose index and effective dose values. Afterwards we looked for differences in quantitative and qualitative evaluation and tried to estimate the frequency of artefact occurrence. The lowest mean value of effective dose was 0,2 ± 0,0 mSv. The results of high pitch protocols in most of the studies were graded as excellent and very few as unevaluable. The difference in quantitative evaluation was very small between the studies. The use of high pitch values enables examinations with very low percentage of moving artefact occurrence. Discussion and conclusion: Based on our results it is possible to conclude that high pitch technique has a great role in lowering the radiation dose while keeping the sufficient image quality. Our study can be a base for further research of mentioned technique and its advantages with the measurments made on CT phantom which could give us objective results of image quality and radiation exposure at the same time.

• Keywords: computed tomography, pitch value, radiation exposure, image quality